1.35" mesh air filter has a (34mm) mounting hole diameter. This filter will also fit anything that has a 1.35" (32-36mm) mounting hole diameter. This filter will give you better air flow than stock, giving you more power. This filter fits most larger carbs. This filter looks much better than the stock filter and is cleanable. This filter will add a personal touch to your Honda CRF50 or XR50. It also fits most Chinese pit bikes and any other types of engines that require a 1.35" filter.